MRI study of the Anterolateral Ligament & its association with Knee injury

Mohammad Salim – Sr. RegistrarShafiq Mohammed – Registrar

Amol Sanap – Sr. RegistrarShreyash Gajjar - Consultant

Introduction

BBC 7 November 2013

NEWS HEALTH “New ligament discovered in knee, Belgian Surgeons say

it could protect as we twist or change direction”

Objectives of the study

• To determine the ease in identifying the ALL on MRI scans.

• To determine any association of tear of ALL with other intra-articular knee injury.

Materials & Method

• 100 Knee MRI scans (98 patients).

Materials & Method

• 161 Knee 3T MRI scans (160 patients).

• M = 105, F = 56.

• Mean age 30.6 years (19-56 yrs).

Materials & Method

• Inclusion criteria - Adults, Knee injury

• Exclusion criteria - Previous Knee surgery - Knee dislocation - OA >Kellegren-Lawrence Gr. II - Inflammatory arthritis - Haemophilia - Knee tumour

Materials & Method• MRI Scan protocol-

• T1 , T2 (fat saturation, PD – Fast spin Echo)

Materials & Method• MRI Scan evaluation - 2 trained Observers - ALL tear +/- assoc. injuries - ALL divided into 3 parts

Materials & Method• MRI Scan evaluation - 2 trained Observers

- ALL divided into 3 parts

Materials & Method• MRI Scan evaluation - 2 trained Observers

- ALL divided into 3 parts

Materials & Method• MRI Scan evaluation

Results

• Entire ALL identified in all 161 knee MRIs (100%).

• Best seen - Coronal plane T2 with fat saturation. - PD weighted fast spin Echo sequences.

ResultsObserver 1 Observer 2

ALL Intact 127 of 161 (79%)

126 of 161 (79%)

ALL Torn 34 of 161(21%) 35 of 161(21%)

ALL + ACL 26 of 66 (39%) 26 of 65 (40%)

Inter-raterAgreement (k)

0.896 – 1.000 (95% CI)

Discussion

Given its structure, anatomic location, the ALL is hypothesized to control internal tibial rotation and thus to affect the pivot shift phenomenon, although further studies are needed to investigate its biomechanical function.

Discussion

• 206 MRI Scans of patients with ACL rupture.• 162 patients (78.8%) – ALL + ACL tear.• Further research reqd. to establish the clinical relevance

of associated radiological ALL damage in ACL injured knees.

Discussion

• It is tempting to speculate that the ALL may have a role in controlling pivot shift. However, more work is needed to confirm its function.

Conclusions• ALL was visualized on all 3T MRI Scans.

• ALL tear was present in 21% knees.

• 40% patients had combined tear of ALL + ACL.

• Clinical studies are reqd. to determine whether ALL contributes to pivot shift ??

Thank-you